Email Indicates More People Knew About Possible Change in Medicare Before It Became Official

WASHINGTON—More people than previously thought predicted a major change in U.S. health-care policy that led to a federal insider-trading probe, according to new documents assembled by congressional investigators.

Justin Simon, a policy analyst with Height Securities, said in a previously unreported email that was reviewed by The Wall Street Journal that he heard about the policy change before it was made official from "like 30...